RU2146008C1 - Rotary engine and method of its operation (versions) - Google Patents

Abstract

FIELD: power engineering; heat engines of various application, including road, air and water vehicles, space plants and high power output industrial thermoelectric plants. SUBSTANCE: proposed rotary engine has housing accommodating driving rotor with sealing projection and driven rotor with two sealing edges and cavity on external cylindrical surface. Rotors are installed for unidirectional rotation. Heating chamber arranged in housing is placed in communication with combustion chamber and expansion chamber through distributing bypass valves on driven rotor and in housing. Rotor profiles are screw type. Antechamber made in housing accommodates recuperative heat exchanger. EFFECT: increased fuel economy and enhanced ecological characteristics of engine. 9 cl, 10 dwg

Description

 The invention relates to the field of energy and can be applied in various types of thermal engines, including ground, air, underwater transport engines, space power plants and powerful units of industrial thermal power plants.

Rotary engines are known from the patent literature:
[1] (SU, copyright certificate 1252509, CL F 01 C 21/16, 08.23.86);
[2] (SU, copyright 1414964, cl. F 02 B 55/00, 08/07/08);
[3] (RU, patent 2013589, class F 02 B 53/00, 10.27.96) - adopted as a prototype.

 [4] (SU, application 94045350, class F 02 B 53/00, 10.27.96), comprising a housing with an internal cavity formed by two intersecting cylindrical bores in which a leading rotor with a sealing protrusion and a driven one are mounted with unidirectional synchronous rotation a rotor with two sealing edges and a hollow on the outer cylindrical surface, kinematically connected by synchronizing gears.

 Inlet caps of the housing have inlet windows for purging the compression chambers with air, exhaust windows are located in the shell of the housing, the combustion chamber is located inside the driven rotor. The rotor profiles are interconnected with minimal gaps and thus form working compression and expansion chambers with non-contact seals. In contrast to the known planetary schemes, the simple rotational movement of the rotors ensures their high peripheral speeds (50 ... 150 m / s) and determines the unique mass and size characteristics of the engine (specific weight less than 0.1 kg / kW). In addition, non-contact seals are the most direct and effective way to create an adiabatic engine, a radical solution to the problems of wear, life, lubrication, reliability, efficiency and environmental friendliness of the engine.

 For example, in the invention [1], the clearance minimization is provided by a gapless synchronization transmission; the device [2] implements active feedback gap control by regulating the thermal regime of the housing; The patent [3] contains a description of a special labyrinth structure providing a "reverse effect", i.e. return leaks during the expansion process back to the expansion chamber; in the application [4] contains a method of sealing the working chambers of the engine directly during operation by condensation and high-speed abrasion in the gaps of relatively soft substances. However, the use of recovery in the engines of the above schemes is difficult, since the combustion chamber is located inside the driven rotor and it is not easy to make the connecting channels between the combustion (heating) chamber and the heat exchanger-recuperator. In addition, the known low-power rotary engines (less than 100 kW) are characterized by a high shaft rotation frequency (n ≈ 18000 rpm), and it is difficult to ensure high-quality and complete combustion of fuel, especially when it is directly injected into the combustion chamber.

 The objective of the invention is to increase fuel efficiency and environmental friendliness of rotary engines.

 The technical result is achieved in that the rotary engine comprises a housing, in the inner cavity of which, with the possibility of unidirectional rotation, a driving rotor with a sealing protrusion and a driven rotor with two sealing edges and a cavity on the outer cylindrical surface are installed. The rotor profiles are made screw. The engine contains a heating chamber located in the housing, equipped with a heat exchanger with an external heat supply or fuel nozzle and spark plug and communicated with compression and expansion chambers through distribution bypass channels made on the driven rotor and in the housing. A precamera is made in the rotor engine housing, the input of which is communicated through the bypass channels with the compression chamber, and the precamera output is communicated with the heating chamber through an additional bypass channel made on the driven rotor. The pre-chamber can be made in the form of a vortex tube with a fuel nozzle. A heat exchanger-recuperator is installed in the pre-chamber, the input of the heating path of which is connected to the exhaust pipe of the engine, and the output is connected to the external atmosphere or through a refrigerator with the engine intake pipe. Distribution bypass channels are made on the outer cylindrical surface of the driven rotor in the form of grooves with ribs - bulkheads, while the grooves of the compression path are communicated through an opening with an expansion chamber. The engine may contain at least two sections, while the same screw rotors of the sections have a different direction of the helix. The volume of the prechamber corresponds to one or more volumes of unit charges of compressed gas from the compression chamber.

 The proposed method of engine operation includes the following processes.

 In the compression chamber, preliminary compression is carried out, the compression chamber with the prechamber is connected to the recuperator and the heating chamber, and additional compression is heated in the recuperator, the heating chamber is disconnected from the prechamber and the expansion chamber, and gas is heated at a constant volume. Then, the heating chamber is connected to the expansion chamber and gas is expanded to a pressure lower than in the prechamber, the prechamber is connected to the heating chamber and blown with compressed gas from the prechamber, the expansion chamber is disconnected from the heating chamber and expansion continues, followed by exhaustion.

 Declared another method of engine operation, including the following processes.

 In the compression chamber, preliminary compression is carried out, then the compression chamber is connected to the prechamber with the recuperator and gas is compressed with heating in the recuperator, the heating chamber is connected to the expansion chamber and preliminary expansion of the previously heated charge to a pressure lower than in the prechamber is performed, the heating chamber is connected to the prechamber and expand the gas from the prechamber to the heating chamber, disconnect the heating chamber from the prechamber and the expansion chamber and supply heat to the gas, connect the heating chamber to In order to expand it, they expand gas to a pressure lower than in the pre-chamber, connect the pre-chamber to the heating chamber and continue expanding the gas until the heated gas is displaced from the heating chamber with a fresh charge, disconnect the expansion chamber from the heating chamber and continue the expansion of the heated gas in the expansion chamber with subsequent release .

 In FIG. 1 shows a motor in cross section along C-C and in the plane of the end face of the driving rotor; in FIG. 2 is a section along A-A; in FIG. 3 - view B; in FIG. 4 - section along the E-E in the phase of the beginning of the expansion process; in FIG. 5 - version of the engine with a long process of heating (combustion) of the charge; in FIG. 6 is a section along M-M; in FIG. 7 is a section along K-K; in FIG. 8 is a section along K-K for a variant with a disk spool; in FIG. 9 shows a variant of a two-section engine; in FIG. 10 shows the design of a gas lubricated seal.

 The engine contains a housing 1 with covers 2.3. In the inner cavity of the housing, formed by two intersecting cylindrical bores, the bearings 4 are equipped with a driving rotor 5 with a sealing lip and a driven rotor 6 with two sealing edges and a cavity on the outer cylindrical surface. The rotors are kinematically connected by a synchronizing gear, providing their unidirectional rotation with equal angular velocity (not shown). In the end caps there are windows 7 connected to the inlet nozzles 8. In the shell of the casing there are outlet windows 9 connected by a channel 10 to the active type turbine blade rim 11 made in one piece with the flywheel fixedly mounted on the shaft 12 of the driving rotor. The output of the turbine 11 is a guide apparatus for the turbine 13 of the turbocharger boost. A pre-chamber 14 and a heating chamber 15 with thermal insulation 16 are made in the housing, which may be in the form of a combustion chamber with a spark plug and fuel nozzle 17 or contain a counter-current heater-heat exchanger with an external heat supply (for example, like a Stirling engine heater). In the pre-chamber 14, a recuperator in the form of a counterflow compact heat exchanger 18, made, for example, in the form of a corrugated sheet of heat-resistant steel, is placed, and the corrugations also have small corrugations, which, when crossed, contact each other at many points and provide the perception of significant pressure drops. The heating path of the recuperator 19 by a pipe 20 is connected to the exhaust gas pipe of the turbine 13, and a pipe 21 is connected to a refrigerator (not shown) and sequentially with the inlet pipe of the turbocompressor (in a closed cycle). When the cycle is open, the pipe 21 is connected to the atmosphere, which serves as a large refrigerator. The volume of the prechamber is satisfied from the condition of placing one charge of compressed air in it, pumped into the prechamber from the compression chamber in one cycle.

где V_к.с. - объем камеры сжатия;
η_v - объемный КПД в процессе сжатия и вытеснения газа в предкамеру;
ε - степень сжатия газа в камере сжатия в конце вытеснения его в предкамеру.Volume of a single gas charge V _g.p. in the pre-chamber is determined by the dependence:

where V _c.p. - volume of the compression chamber;
η _v - volumetric efficiency in the process of compression and displacement of gas in the chamber;
ε is the degree of compression of the gas in the compression chamber at the end of its displacement in the chamber.

The axial rotor profiles are twisted along a helical line; the angle of twist of the ends within the length of the working chamber in FIG. 1, 2 is approximately 30 ^o . The screw rotors make it possible to eliminate excessively high gas velocities and hydrodynamic losses at the end of the compression process and at the beginning of the expansion process, to increase smoothness of work and uniformity of torque.

On one of the cylindrical ends of the outer surface of the driven rotor, bypass distribution channels are made in the form of recesses 22 with longitudinal ribs-bulkheads 23. The recesses at the end of the compression process by channels 24 in the housing cover are connected to the inlet of the prechamber and the hole 25 in the rotor communicates with the expansion chamber after the process phase expansion, corresponding to the pressure drop in the expansion chamber to a level less than the pressure in the pre-chamber. At the other end of the driven rotor, bypass channels 26 are made, by means of which holes 27, 28 of the pre-chamber 14 are in communication with the input of the heating (combustion) chamber 15 during compression. The heating chamber has the shape of a sphere, a compact cylinder or another body of revolution, the entrance to it 28 and exit 29 are located tangentially and axially spaced to provide direct-flow swirling conditions; at the beginning of the expansion process, the outlet 29 through the bypass channel 26 and the recess 30 in the housing cover is connected to the expansion chamber. At the same end of the driven rotor there is an additional recess 31, through which the pre-chamber and the heating chamber are connected when the pressure in the expansion chamber becomes less than the pressure in the pre-chamber. On the end and cylindrical surfaces of the casing mating with the rotors, it is advisable to install gas lubricated seals 5, which are a single or split ring 32 (see Fig. 10) with an internal cavity connected by a pipe 33 to a source of compressed air and throttling holes 34 - with macro grooves or pockets on the sealing surface of the ring. The ring is installed in the groove of the housing and preloaded by a wave spring 35. Tests of a prototype of such a seal confirmed its high efficiency. The engine can be made two-section with two working cavities separated by a middle cover 36 (see Fig. 9) with a common synchronizing gear with gears 37, 38 (the third intermediate “spurious” gear is not visible in this section). The rotors of the same name in different sections have different (right and left) directions of the helix, the driving rotors (therefore, the driven ones too) are installed in different sections either in phase (in this case, the axial component of the gas pressure force is mutually compensated), or in antiphase, etc. e. with an offset of 180 ^o (as in Fig. 9), which ensures high uniformity of torque and reduction of pulsation of the gas flow in the turbine 13. The recesses 26, 31 are performed on the driven rotor in antiphase, i.e. on the contrary, they are common for both cavities and function with double intensity, which is accompanied by a decrease in passive volumes and leaks.

 The method of engine operation includes the following processes. Compressed air is supplied to the compression chamber through the pipe 8 and the window 7 from the turbocompressor, and preliminary compression of the air to a pressure of about 10 bar is carried out in the compression chamber.

 After that, the compression chamber by recesses 22 and channels 24 is connected to the input of the recuperator 18 in the pre-chamber 14, and the output of the recuperator through channel 27, the notch 26 and channel 28 is connected to the heating chamber 15, and additional compression is performed. In this case, the compressed air in the heat exchanger is heated by exhaust gas from 590 to 1400 K and enters the heating chamber.

At the end of the compression process, the air pressure rises to 23 bar, its temperature in the heating chamber due to adiabatic compression in the latter reaches about 1600 K. After that, the heating chamber is disconnected from the pre-chamber and expansion chamber, and fuel is injected through the nozzle 17 (or heating from an external heat source through a heat exchanger), which ignites from a high air temperature and quickly burns out at a constant volume of the heating chamber, the gas temperature rises to ~ 2800 K, the combustion phase at a constant volume of Corresponds to an angle of ~ 40 ^o rotation of the rotors, pressure up to ~ 42 bar.

 Then, the heating chamber is connected to the expansion chamber 39 through the channel 29 and through the recesses 26 and 30, where the heated gas is pre-expanded to a pressure less than in the pre-chamber (up to about 22 bar).

 At this point, the pre-chamber is again connected to the heating chamber by means of an additional recess 31 and subsequent expansion occurs simultaneously in the expansion chamber, the heating chamber and in the pre-chamber, and air from the pre-chamber blows out the heating chamber, eliminating the negative effect of residual gases. At the end of the purge, the heating chamber is disconnected with the expansion chamber at a gas pressure of about 10 bar, further expansion takes place in the expansion chamber until the outlet window 9 is opened. The exhaust gases pass through the channel 10 into the active turbine 11, which is also a flywheel, then they are triggered in the turbine 13 of the turbocharger, enter through the pipe 20 into the heating path 19 of the recuperator, give heat to the working fluid, exit through the pipe 21 to the refrigerator (or to the atmosphere) and, in a closed cycle, to the inlet pipe of the turbocharger. The compressed air remaining in the channels 22, through the holes 25 enters the expansion chamber and does useful work in it.

 The design of the engine with gas control valves by bypass channels-recesses allows to exclude valves from the device, to increase reliability and speed.

 Simplified design options are possible with the implementation of traditional working methods. For example, the engine can be performed without a pre-chamber and additional recesses 31, while the heating chamber is connected via the bypass channels 26, 22 directly to the expansion and compression chambers.

 In another version, the pre-chamber remains, but it is executed without a recuperator in the form of a vortex tube equipped with a fuel injection and gas-air mixture preparation device, which is ignited in the combustion chamber by the spark plug, while the flame propagation in the pre-chamber is eliminated by the high speed of the mixture in the bypass channels, exceeding the propagation velocity flame front. FIG. 5, 6, 7, 8 illustrate the device and method of engine operation, in which the advantages mentioned above are greatly enhanced. The bypass channels of the compression path are arranged similarly to FIG. 1, 2, 3, the volume of the prechamber 14 with the recuperator is larger, it includes several (2 ... 10) - unit volumes coming from the compression chamber in one cycle. The phase position of the additional recess 31 is changed. The channels 26 are made with bulkhead ribs. Their output opens directly into the expansion chamber 39 (without chamfer 30), which reduces the passive volume of the notches and the length of the driven rotor for their placement. Bulkheads can reduce the hydrodynamic losses from shock expansion of the gas into the volume of the recesses when they are filled and to reduce leakage in the gaps between the rotors at the moment of coupling of the recesses with the surface of the leading rotor. In FIG. 8 shows another embodiment of the bypass channels, in which the driving rotor is provided with a disk protrusion 40, in which a bypass window 41 is made connecting the heating chamber to the expansion chamber. Similarly made bypass channel compression path. This option is characterized by a reduced passive volume of the window 41 and a lower hydrodynamic resistance due to the small angle of rotation of the jet. The disadvantage is some complication of the design and assembly of the node.

The method of engine operation includes the following processes. In the compression chamber, preliminary compression is carried out. Then, the compression chamber with the prechamber is connected to the recuperator and gas is compressed by heating it in the recuperator. The heating chamber 15 through the channels 29, 26 is connected to the expansion chamber 39 and carry out the preliminary expansion of the previously heated charge to a pressure less than in the pre-chamber. Next, the heating chamber through the channels 28, 31, 27 is connected to the pre-chamber 14 and in the operation phase corresponding to FIG. 5, gas expands from the prechamber to the heating chamber, and from the latter to the expansion chamber. After purging the heating chamber, it is disconnected from the pre-chamber and expansion chamber, fuel is injected into it, ignition occurs with a very long combustion process (the combustion phase in an insulated constant volume can last up to ~ 300 ^{o of the} angle of rotation of the rotors), its optimal duration is adjusted in the usual way by changing the angle injection lead. A longer heating time is also advisable when using a heater-heat exchanger with an external supply of heat.

 The heating chamber is connected to the expansion chamber and gas is expanded to a pressure lower than in the prechamber. The prechamber is connected to the heating chamber and gas expansion continues until the heated gas is displaced from the heating chamber with a fresh charge. Disconnect the expansion chamber from the heating chamber and continue the expansion of the heated gas in the expansion chamber with subsequent release.

 For the successful implementation of an engine with non-contact seals, it must be very fast. For example, an engine with dimensions corresponding to FIG. 1.5, it can have a nominal shaft speed of about 24,000 rpm at a power of ~ 50 kW, under these conditions a large phase duration seems necessary for high-quality and complete combustion of fuel.

 The increase in the volume of prechambers with a recuperator several times, respectively, increases the completeness of heat transfer and the efficiency of the recuperator.

 It is advisable to cover the heat exchange surfaces of the recuperator and heater, for example, with catalytic converters to eliminate exhaust toxicity. Non-contact seals of the working chambers do not need lubrication, which eliminates carbon deposits and other deposits in the heat exchangers-neutralizers caused by the release of oil, which reduce the reliability of the latter.

The above way of working can be changed. Gas displacement from the compression chamber and expansion from the heating chamber can occur simultaneously, but this requires a strong screw twist of the rotors with a relatively small pitch of the helix, at which the profiles at the ends of the rotors are rotated by about 180 ^o C. With a two-section motor design, the rotors can have the usual screw twist (~ 30), in antiphase in adjacent sections (that is, they must be rotated in different sections by 180 ^o ), while the compression occurs in one section and the simultaneous expansion in another; moreover, it is possible to use one common heating chamber.

 The engine is operable as a steam engine with a two-phase working fluid, for example, with water, freon, carbon dioxide, etc. The proposed methods of operation are suitable for implementation in piston engines with a valve or spool valve algorithm corresponding to these methods.

Claims (9)

 1. A rotary engine containing a housing in the inner cavity of which with the possibility of unidirectional rotation, a driving rotor with a sealing protrusion and a driven rotor with two sealing edges and a cavity on the outer cylindrical surface, a compression, heating and expansion chamber, an inlet and outlet pipe, characterized in that the heating chamber is located in the housing, is equipped with a heat exchanger with an external heat supply or fuel nozzle and spark plug and is in communication with the compression and expansion chambers through the distribution solid bypass channels made on the driven rotor and in the housing, and the profiles of the rotors are made screw.  2. The engine according to claim 1, characterized in that the pre-chamber is made in the housing, the input of which is communicated through the bypass channels with a compression chamber, and the output through an additional bypass channel made on the driven rotor with a heating chamber.  3. The engine according to claim 2, characterized in that the prechamber is made in the form of a vortex tube with a fuel nozzle.  4. The engine according to claim 2, characterized in that a heat exchanger-recuperator is installed in the prechamber, the input of the heating path of which is connected to the exhaust pipe of the engine, and the output is connected to the external atmosphere or through a refrigerator with the engine intake pipe.  5. The engine according to claim 1, characterized in that the distribution bypass channels are made on the outer cylindrical surface of the driven rotor in the form of recesses with bulkhead ribs, while the recesses of the compression path are communicated through an opening with an expansion chamber.  6. The engine according to claim 1, characterized in that it contains at least two sections, while the same screw rotors of the sections have a different direction of the helix.  7. The engine according to claim 2, characterized in that the volume of the prechamber corresponds to one or more volumes of unit charges of compressed gas from the compression chamber.  8. The method of operation of the engine, including filling the compression chamber with gas, compressing it, heating in the heating chamber, expanding and discharging from the expansion chamber, characterized in that the compression chamber is precompressed, the compression chamber with the prechamber is connected to the recuperator and the heating chamber, and produced additional compression with heating in the recuperator, disconnect the heating chamber from the pre-chamber and the expansion chamber and produce gas heating at a constant volume, connect the heating chamber to the expansion chamber and expand over to a lower pressure than in the antechamber, the antechamber is connected with the heating chamber and purged with compressed gas from the pre-chamber, the expansion chamber is disconnected from the heating chamber and continue expansion with subsequent release.  9. The method of operation of the engine, including filling the compression chamber with gas, compressing it, heating in the heating chamber, expanding and discharging from the expansion chamber, characterized in that the compression chamber is precompressed, then the compression chamber is connected to the prechamber with a recuperator and gas is compressed with heating it in the recuperator, connect the heating chamber to the expansion chamber and carry out preliminary expansion of the previously heated charge to a pressure lower than in the prechamber, connect the heating chamber to the prechamber and they allow gas expansion from the prechamber to the heating chamber, disconnect the heating chamber from the prechamber and the expansion chamber and supply heat to the gas, connect the heating chamber to the expansion chamber and expand the gas to a pressure lower than in the prechamber, connect the prechamber to the heating chamber and continue gas expansion until the heated gas is displaced from the heating chamber with a fresh charge, the expansion chamber is disconnected from the heating chamber and the heated gas continues to expand in the expansion chamber with subsequent release.

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